Food stuffs such as coffee, nuts, fruits and jams etc. are vacuum packed in order to maintain freshness for delivery to the consumer. Obviously however, the products begin to loose freshness the moment the container is opened and the vacuum lost to the surrounding atmosphere which is normally humid to a substantial degree. Therefore, hermetic closures have been attempted but even then the capture of air at atmospheric pressure subjects the product to the permeation of dampness. On the contrary, the reestablishment of a partial vacuum would impose the depressurization known to be so beneficial in maintaining freshness, and to this end it is a general object of this invention to provide a closure that draws a vacuum upon a container to preserve the freshness of the product previously vacuum packed therein. With the present invention, installation of the Vacuumizing Closure substantially reduces atmospheric pressure within the container so as to draw moisture from the product stored therein, thereby eliminating the otherwise expected gradual but continuous permeation of moisture leading to staleness of the product.
The application to containers of the usual stoppers, plug-in and screw-in closures, tends to compress the interior rather than to depress the same, and thereby impresses the atmospheric humidity upon the product remaining therein. The greater the volume of remaining product the greater is the compressive and/or depressive effect, due to the smaller remaining container space to be filled by said atmosphere. However, the lesser the volume of remaining product the greater is the remaining container space inherently filled with atmospheric humidity to have its adverse effect upon the product. Accordingly, it is an object of this invention to provide a closure that initially occupies the chamber together with the product therein, to draw atmospheric humidity therefrom.
Containers for food stuffs are not filled to their brim, but are filled to a level which constitutes a measured portion either by weight or by volume. In any case, the fill level is below the container rim, and it is from this level that a portion of the product will be taken at the first opening of said container. For example, when brewing coffee the product level will be approximately an inch below the container rim after withdrawing sufficient coffee to brew a large pot thereof; and it is this measurement which determines the depth to which the present closure penetrates and which determines the draw of partial vacuum thereby. It is an object therefore, to maximize the closure occupancy to thereby maximize the drawing of a partial vacuum. With this invention, the closure enters into the container to the level of product therein, preferably after a normal portion thereof has been removed, thereby maximizing the vacuum effect.
The resealing of containers such as metal cans is a problem once the hermetic seal of the integral lid is broken, as for example by complete removal of said lid. With the usual beaded can construction, the rolled and/or crimped bead of the can is left to present a circumferential rim of smooth uniform cross section, distorted to some extent perhaps by slight imperfection in manufacture and by bending during the can opening process. Accordingly, it is an object of this invention to reestablish a hermetic seal with the bead left remaining at the circumferential rim of the can, to seal with the inner and outer diameters of the bead.
It is a general object of this invention to provide a Vacuumizing Closure of the character hereinabove referred to that is simple and economical of manufacture, and a device that is inherently practical for the purpose intended of drawing a partial vacuum upon the remaining content of a glass or jar or can and any such vessel that has been opened and/or which requires closure, so as to establish a hermetic seal with the bead at the otherwise opened end thereof, a feature of the invention being the simplicity of application and removal which requires but a single movement of an actuating lever in each instance.